Commitments and Contingencies - Lease Maturity Schedule (Details) - USD ($) $ in Thousands	Jul. 31, 2019	Apr. 30, 2019
Capital leases
2020	$ 3,104
2021	3,112
2022	3,119
2023	3,099
2024	2,113
Thereafter	8,884
Total minimum lease payments	23,431
Less amount representing interest	7,357
Present value of net minimum lease payments	16,074
Operating leases
2020	1,969
2021	1,907
2022	1,850
2023	1,765
2024	1,666
Thereafter	27,328
Total minimum lease payments	36,485
Less amount representing interest	14,251
Present value of net minimum lease payments	$ 22,234
Capital leases
2020		$ 3,103
2021		3,109
2022		3,096
2023		3,098
2024		2,548
Thereafter		9,215
Total minimum lease payments		24,169
Less amount representing interest		7,689
Present value of net minimum lease payments		16,480
Operating leases
2020		1,703
2021		1,547
2022		1,354
2023		1,228
2024		1,066
Thereafter		10,438
Total minimum lease payments		$ 17,336